1. Field of the Invention
The present invention relates to a volume control system having an amplifying apparatus and a controller.
2. Description of the Related Art
AV amplifier is connected to PC via network such as LAN, and contents reproduction is controlled by control program (hereinafter, controllers) installed into the PC. Server program (hereinafter, servers) is also installed into the PC, and a plurality of audio files are recorded in HDD of the PC. When audio file recorded in the HDD is selected by users' operation, the controller transmits instruction for reproducing the selected audio files to the AV amplifier. The AV amplifier requests the server to transmit the selected audio files. The server reads the selected audio files from the HDD and transmits them to the AV amplifier. The AV amplifier decodes the audio files transmitted from the server, and amplifies them so as to output sounds through speaker.
When instruction for changing controller-side volumes value is input by users' mouse operation, the controller transmits the changed controller-side volume value to the AV amplifier. Accordingly, the AV amplifier controls the volume value at the time when the AV amplifier amplifies sound signals. Slide bar for changing the controller-side volume value by means of users' operation is provided to operation screen of the controller, and when the slide bar is moved, the controller-side volume value is changed so that the volume value of the AV amplifier is controlled. Therefore, it is demanded that the volume of the AV amplifier is suitably (namely, clearly for the users) is changed according to the changes in the controller-side volume values.
Further, when the user increases the controller-side volume value to maximum value (or around the maximum values) at a stroke, the volume value of the AV amplifier rises to the maximum values (or around the maximum values). As a result, amplifying circuit and speaker of the AV amplifier might be damaged.
With a volume control apparatus suggested in Japanese Patent Application 2009-281064 by the applicant of this application, as described above, a volume of an AV amplifier can be controlled according to a controller-side volume value transmitted from the controller. However, since the controller cannot recognize the volume value of the AV amplifier, when a user operates a volume knob or a remote controller of the AV amplifier to control the volume value of the AV amplifier, the controller-side volume value set in the controller becomes different from the actual volume value of the AV amplifier. As a result, the volume of the AV amplifier cannot be suitably changed according to a change in the controller-side volume value.